Electrical clock movement



R. WOLBER ETAL 3,375,653

A ril 2, 1968 ELECTR I CAL CLOCK MOVEMENT 2 Sheets-Sheet 1 Filed July 12, 1965 Fig. 2 211 April 1968 R. WOLBER ETAL 3,375,653

ELECTRICAL CLQCK MOVEMENT 2 Sheets-Sheet :v

Filed Jfily 12, 1965 INVENTORS mmawwwm United States Patent Qfiice 3,375,653 Patented Apr. 2., 1968 3,375,653 ELECTRICAL CLOCK MOVEMENT Robert Wolber, Lauterbach, Wurttemberg, Otto Hettich, Schramberg, Wurttemberg, Horst Fehrenbach, Seedorf, Wurttemberg, and Heinz Armbruster and Friedrich Assmus, Schramberg, Wurttemberg, Germany, assiguors to Gebriider Junghaus Aktiengesellschaft, Schramberg, Wurttemberg, Germany, a corporation of Germany Filed July 12, 1965, Ser. No. 471,207 Claims priority, application Germany, Nov. 2, 1964, J 26,802; June 8, 1965, J 28,305 3 Claims. (CI. 5828) The invention relates to an electrical clock movement having a torsion oscillator which drives the wheel mechanism and is preferably kept oscillating by contactless means via a known electronic circuit, for example a semiconductor amplified circuit.

Such clock movements are known per se. The invention is based on the problem of designing a movement of this kind in such manner that, whilst exhibiting satisfactory operating qualities, it can be manufactured simply and with the minimum expenditure. Consequently, it is one of the objects of the invention to so arrange the wheel mechanism of a clock of the type mentioned that it requires little space and can be mounted with only a few bearing points.

It is a further object of the invention to provide a clock motion having a case, preferably made of plastics material, in which the clock movement can be secured in a simple manner, without the clock plates warping or buckling, since this might result in increased bearing friction or even in jamming.

It is yet a further object of the invention to provide a stepping device for a clock movement of the abovediscussed type, by means of which reliable operation is assured, in particular avoiding abrasion of the stepping wheel teeth on the protective faces of the stepping fork and rotating-back of the stepping-wheel.

It is a further object of the invention to provide a contact device for the connection of a battery with the drive circuit, which said conact device can be manufactured simply and ensures a reliable electrical con tact, entirely satisfactory retaining of the battery and also simple replacement thereof.

The invention is characterised in that, in a clock movement of the type discussed at the outset, all the wheels, with the exception of the stepping wheel, are arranged to pivot about only two arbors one of which is the hours shaft arbor.

In a clock movement having a case made for example of plastics material, the movement is secured, preferably with its carrier, for example the front plate, in the case With the aid of posts disposed closely together.

The clock movement is preferably provided with a stepping fork which for every half oscillation of the torsion pendulum steps-on the stepping wheel by the amount of half a tooth pitch. In this case, there is preferably associated with the stepping wheel a lock gear having double the number of teeth relative to the stepping wheel and having an adjustable locking member engaging in the toothing.

For the connection of a battery with the torsion pendulum drive circuit one of the clock plates, preferably the front plate, may be formed with a punched-out tongue to the free end of which a retaining element for the battery is secured.

The invention is discuss-ed in greater detail in the following text, with reference to various examples of embodiment and with reference to the drawings, wherein:

FIGURE 1 shows an embodiment of a stepping device,

as a longitudinal section through the stepping wheel and the lock gear,

FIGURE 2 shows a part elevation of a clock movement with the lock gear according to FIGURE 1,

FIGURE 3 shows a further part elevation of the movement according to FIGURE 2,

FIGURE 4 shows a part elevation corresponding to FIGURE 2 of a clock movement having a lock gear with teeth,

FIGURE 5 shows an enlarged illustration of a part of the stepping wheel with the lock gear according to FIGURE 4.

FIGURE 6 shows an illustration of the stepping procedure of the stepping wheel by means of the stepping fork illustrated,

In the drawings reference numeral 210a designates a lock gear directly connected with the stepping wheel 21%; for example, the two wheels are in one piece. They are arranged on the shaft 218. Reference numeral 210C designates the teeth of the lock gear, 210a and 210d designate the teeth of the stepping wheel 21012 which are stepped-on in known manner by means of the stepping fork 212 arranged on the balance staff 211.

The bent-over end 213a of the lock or click spring 213 engages in the toothing 2100 of the ratchet wheel 210a. The teeth of the lock gear 210a are approximately triangular, so that the bent-over end 21312 of the lock spring 213 retains the stepping wheel 21Gb in a clearly defined inoperative position.

The end 2131) of the lock spring 213 remote from the lock gear 210a is fast in a cylinder 214 which is a friction fit on a stationary post 215. The cylinder 214 is formed with a slot 214a for receiving a tool, for example a screwdriver with the aid of which the cylinder can be rotated on the stationary post 2 15. By rotating the cylinder 214, the position of the bent-over portion 213a of the lock spring 213 can be varied relatively to the lock gear 210a in the longitudinal direction of the lock spring, by which means the position of a tooth 210d of the stepping wheel 21Gb can be varied in the inoperative position of the ratchet wheel. The adjustment is effected in such manner that the tooth of the stepping wheel 2101) located in the stepping fork 212 is so positioned that it does not scrape against the guides of the stepping fork.

The eccentric 216 is riveted, with friction, into the intermediate bridge 217 in such manner that it can be rotated with the aid of a screwdriver. With the aid of the said ececntric 216, the force with which the end 213a of the lock spring 213 bears against the lock gear 210a can be adjusted. The adjustment is effected in such manner that on the one hand the stepping Wheel 2101: is effectively locked in the inoperative position whereas on the other hand the oscillation of the balance is damped to the minimum extent.

The lock spring 213, the cross-section of which ispreferably rectangular, may 'be made of any desired metal material having resilient properties.

The illustration according to FIGURE 4 differs from that according to FIGURE 1 only with regard to the stepping wheel 220 with the lock gear 221, which is provided with a special toothing, as shown to an enlarged scale in FIGURE 5.

Reference numeral 220a designates the teeth of the stepping wheel, the pitch angle of which is designated beta. The teeth of the lock gear 221 have a special shape, the front tooth flank in the rotation or stepping direction forming one plane, whereas the rear tooth flank 2 as seen in the stepping direction forms planes 221b and 221d which are inclined at an angle relatively to each other and meet at 2210. Thus, in its upper portion, this rear tooth flank forms a step which reliably prevents turning-back of the stepping wheel 220 or of the lock gear 221.

The mode of operation of the lock gear 221 illustrated in FIGURES 4 and 5, together with the stepping-on of the stepping wheel 220 by the stepping fork 212 will now be discussed with reference to FIGURE 6.

In FIGURE 6, reference numeral 212 designates the fork plates and reference numerals 212a and 212b the stepping or lifting faces. Reference numeral 220a designates the stepping Wheel teeth, shown in the position which they adopt in the inoperative position of the balance.

FIGURE 6 shows, in broken lines, further positions of the central stepping wheel tooth, as adopted thereby during the oscillation of the balance; however, the stepping Wheel teeth move in reality on the line II shown in FIGURE 6, during the movement of the stepping fork 212. In order to simplify the drawing, they are shown, in FIGURE 6, displaced with respect to the stepping fork 212.

When the stepping fork 212 effects, out of the inoperative position, a movement through the angle a (approximately 17), the stepping wheel tooth 220a reaches the position 220a in which it contacts the stepping or lifting face 212a of the stepping fork 212. Up to this instant, the tip of the click spring 212 is in the tooth dedendum of the lock gear 220, as shown in full lines in FIGURE 5.

During the further movement of the stepping fork 212, through the angle a (approximately 38), the tip of the lock spring 213 is lifted by the front (as seen in the stepping direction) tooth flank 212a, When the stepping wheel tooth is in the position 2201:" the tip of the lock spring 213 has slid over the corresponding tooth addendum of the lock gear 221 and has adopted the position designated 213 in FIGURE 5. In FIGURE 5, reference numeral 222 designates an arc of a circle showing the path of movement of the tip of the lock spring 213. The shoulder 221b of therear (as seen in the stepping-on direction) tooth flank of the lock gear corresponds approximately to the shape of the arc of a circle 222; it may also be somewhat undercut, so that the tip of the lock spring 213, after sliding over one tooth addendum of the lock gear 221, immediately drops down on to the tooth flank or part 221d to position 213", shown in FIGURE 5, so that its tip is on the edge 221c. On further rotation of the stepping fork through the angle a (approximately 5), the stepping wheel 220 is rotated further through a small angle into the position 220a shown in FIGURE 6. At the same time, the tip of the lock spring 213 slides on the tooth flank portion 221d but not quite as far as the dedendum 2212. On the contrary, the remaining rotation of the stepping wheel 220, i.e. into the position 220a" of the stepping wheel tooth, is effected by the pressure of the click spring tip on the tooth flank portion 221d, until the tip of the lock spring has reached the tooth dedendum 221e. The ratchet wheel tooth then adopts, as already explained, the position designated 220a" in FIGURE 6, in this way preventing abrasion of the stepping wheel teeth on the fork plates.

If the Wheel train of the clock is soiled or if friction is increased due to any other reason, a 'backwardly directed torque may be exerted on the lock gear 221, so that the lock spring 213 may he lifted slightly once more by the tooth flank portion 221d, but only into the position designated 213" in FIGURE 5; in this position, the tip of the lock spring 213 impinges against the shoulder 221b, so that further rotation-back-of the lock gear and therewith of the stepping wheel is reliably prevented.

In FIGURE 5, the pitch angle of the stepping wheel is designated [3. The pitch angle of the lock gear is designated [3 It is half the size of the pitch angle ,8. B is the angle of torque of the lock gear, produced by the lifting of the stepping fork when the latter moves through the angle (1 a is the remaining movement angle of the lock gear after which the lock spring 213 adopts the safety or Securing position.

What is claimed is:

1. Electric timekeeping mechanism with a driving balance and shaft which is kept oscillating by electromagnetic means, comprising a branch'switch consisting of accelerating surfaces directed at an acute angle relative to the shaft and arranged on the balance shaft, adjoining safety surfaces directed perpendicularly in relation to the shaft, a stepping wheel moved on by one tooth division of the stepping wheel for each' half oscillation of the balance shaft, a lock gear for 'the' stepping wheel with double the number of teeth as compared to the stepping wheel, and a lock spring adjustable relative to its length and its pre-tension in relation to the lock gear and meshing with its free end with said teeth, whereby the teeth surfaces of the lock gear, which, relative to the direction of rotation are in back, form a shoulder and the profile of which corresponds approximately to the plane described by the point of the lock spring in its movement.

2. Electrical clock movement according to claim 1, in which the lock gear is formed with teeth which, on rearward rotation of the ratchet wheel forms a stop for the lock spring, and having an undercut surface.

3. Electrical cloc-k movement according to claim 1, in which the lock gear is formed with teeth which, on rearward rotation of the lock gear forms a stop for the lock spring and having an undercut surface, and the tooth flank portion following the step in inclined relationship in such manner that the ratchet and with it the stepping wheel, is further-rotated by the pressure acting thereon of the spring tip, until the click tip has reached a tooth end.

References Cited UNITED STATES PATENTS 2,590,365 3/1952 Anderson S8--28 3,001,305 12/1961 Jensen 58-28 1,603,370 10/1926 Wilcox 5853 3,090,193 5/1963 Jensen 58-53 2,926,534 3/1960 Fritsch 74-126 2,981,117 4/1961 Studer 74-126 2,907,810 10/1959 Detwiler et a1. 136173 2,985,705 5/1961 Smythe 136-273 2,800,763 7/1957 Ensign et a1 5828 FOREIGN PATENTS 666,179 9/ 1929 France. 1,255,852 1/1961 France.

165,203 2/ 1934 Switzerland.

344,371 3/1960 Switzerland.

RICHARD B. WILKINSON, Primary Examiner.

S. A. WAL, G. F. BAKER, M. LORCH,

' Assistant Examiners.

UNITED STATES PATENT OFFICE Certificate Patent No. 3,375,653 Patented April 2, 1968 Robert Wolber, Otto Hettich, Horst Fehrenbach, Heinz Armbruster, and Friedrich Assmus Application having been made by Robert Wolber, Otto Hettich, Horst Fehrenbach, Heinz Armbruster, and Friedrich Assmus, the inventors named in the patent above identified, and Gebruder Junghans G.m.b.H., a corporation of Germany, the assignee, for the issuance of a certificate under the rovisions of Title 35, Section 256, of the United States Code, deleting the names oi Horst Fehrenbach, Heinz Armbruster, and Friedrich Assmus as joint inventors, and a showing and proof of facts satisfying the requirements of the said section having been submitted, it is this 27th day of N ovember 1973, certified that the names of the said Horst Fehrenbach, Heinz Armbruster, and Friedrich Assmus are hereby deleted from the said patent as joint inventors with the said Robert Wolber and Otto Hettich.

FRED W. SHERLING, Associate Solicitor. 

1. ELECTRIC TIMEKEEPING MECHANISM WITH A DRIVING BALANCE AND SHAFT WHICH IS KEPT OSCILLATING BY ELECTROMAGNETIC MEANS, COMPRISING A BRANCH SWITCH CONSISTING OF ACCELERATING SURFACES DIRECTED AT AN ACUTE ANGLE RELATIVE TO THE SHAFT AND ARRANGED ON THE BALANCE SHAFT, ADJOINING SAFETY SURFACES DIRECTED PERPENDICULARLY IN RELATION TO THE SHAFT, A STEPPING WHEEL MOVED ON BY ONE TOOTH DIVISION OF THE STEPPING WHEEL FOR EACH HALF OSCILLATION OF THE BALANCE SHAFT, A LOCK GEAR FOR THE STEPPING WHEEL WITH DOUBLE THE NUMBER OF TEETH AS COMPARED TO THE STEPPING WHEEL, AND A LOCK SPRING ADJUSTABLE RELATIVE TO ITS LENGTH AND ITS PRE-TENSION IN RELATION TO THE LOCK GEAR AND MESHING WITH ITS FREE END WITH SAID TEETH, WHEREBY THE TEETH SURFACES OF THE LOCK GEAR, WHICH, RELATIVE TO THE DIRECTION OF ROTATION ARE IN BACK, FORM A SHOULDER AND THE PROFILE OF WHICH CORRESPONDS APPROXIMATELY TO THE PLANE DESCRIBED BY THE POINT OF THE LOCK SPRING IN ITS MOVEMENT. 